Online washability: Comparison of dual parameter and triple parameter analysis

Abstract

Growing demand on coal quality leads to the need of enhanced analysis tools for coal parameters. Therefore fast analysis of washability properties becomes a must in coal preparation. The washability monitor OREGON which was introduced to the coal market in 2012 uses the combination of optical and radiometric methods for the fast determination of the washability curve. The concept of the analyzer is based on the measurement of a sample which will be processed in about 20 to 30 minutes. The sample is fed through the analyzer on a conveyor belt in a single layer. Each particle is characterized by size and density. The washability characteristics of the full sample are then generated by Statistical evaluation. The method does not utilize any chemicals and the analysis can be performed even by untrained personell. Basic techniques which are used for analysis were first presented at ICPC 2010. It is obvious that basic combination of radiometric dual energy measurement leads to inaccuracies if ash composition undergoes variations. This effect is well known from dual energies ash gauges. Therefore the analyzer utilized a combination of dual energy and optical measurements. The paper discusses the improvements which are achieved by the triple parameter measurement concept in comparison to alorithms based on only two parameters.